Patent GB-987586-A (GB)
Title: Welding apparatus
IPC: B23K9/22
Filed: 1962-01-25
Abstract: 987,586. Making electric switches; welding by pressure shearing. WESTERN ELECTRIC CO. Inc. Jan. 25, 1962 [Feb. 24, 1961], No. 2787/62. Headings B3A, B3R and B3W. [Also in Division B4] In a machine in which a percussion welding head welds a wire to an article, the article is moved after welding to draw a predetermined length of wire through the welding head and the wire is severed by a cutting device to provide a new end to be welded to another article. The machine welds two wires 21, Fig. 17, to the terminals 22 of a dry reed switch 23, cuts the wires 21 to length, cuts insulating tubing into sleeves 27, Fig. 18, and positions the sleeves 27 over the terminals 22 to leave the wires 21 projecting as leads 24. All moving parts are actuated by cams on shaft 29. Feeding switches and welding.-Switches 23 are gravity fed with the aid of an oscillatable roll 37 from a hopper 31 on to members 54 on a horizontal slide 42. With the slide 42 in its retracted position the members 54 are retracted sufficiently to actuate a plunger 41 to free the leading switch 23 which falls in front of the members 54 on to electrodes 46 on the slide 42. As the slide 42 moves forward, spring-loaded cam-controlled clamps 52 grip the ends of the terminals 22 and contacts 48 on the slide 42 engage spring-loaded contacts 49 to connect one side of a bank of condensers to the electrodes 46. The plunger 41 is freed to brake the movement of the switches 23 in the feed path 34 and to stop the machine if no switch is present. Wires 21 are simultaneously welded to each terminal 22 when the slide 42 is in its forward position. Each welding head 47, Fig. 9, consists of two interlocking parts 58, 59 urged apart by a spring 61 and sliding in a block 57. The lower part 59 is connected by a lead 66 to the other side of the bank of condensers and houses a spring-loaded wire-gripping jaw 63. The head 47 is raised by engagement of a pin 68 with a cam-wheel 69 actuated by a pawl and ratchet mechanism 71, 72, and shortly after the up-stroke is commenced the jaw 63 is released to grip the wire 21 which loops slackly between the head 47 and a guide wheel 62. When the wheel 69 releases the pin 68 a spring 67 forces the head down to weld the wire 21 to the terminal 22, excess impact, and rebound being absorbed by the spring 61. The jaw 63 is opened by a cam-actuated member 76. Apertures in the electrodes 46 receive the wires 21 if no switch 23 is present to prevent welding of the wires 21 to the electrodes 46. Shearing.-The switch is gripped by jaws 94, 96 on a slide 93 carried on a pivoted guide 87 and, as the carriage 42 is retracted, is transferred on to slots 133a in rotary units 133, the wires 21 being pulled through the welding heads 47. The wires 21 are severed close to the heads 47 by two shears 109 having pairs of blades 117, Figs. 6 and 13, which have wedge-shaped blunt cutting edges, which when closed do not meet. Each pair of blades 117 is spring-loaded apart and mounted on a cam slide 111 reciprocated by a lever 114 carrying a leaf-spring 113 engaging a pin 111a on the slide 111. The lever 113 through a lost-motion connection 127 rotates a detent 123 which when the blades 117 are open with a wire 21 in between releases a pair of spring-actuated rods 118 which impact on the blades 117 with sufficient force to form wedgeshaped ends on the wire 21 and to sever the wire even though the blades 117 do not meet. Positioning of sleeves 27 on the terminals 22.- Insulating tubes 26 are fed through holes 136 in fixed discs 132 into bores 134 in the rotary units 133 by a reciprocating gripper mechanism 146 actuated by a lever 158, the length of feed being adjusted by stops 162, 163. The units 133 when rotated by a common pawl and ratchet device 142 sever the portions of the tubing in the bores 134 to form the sleeves 27. The lever 158 also actuates two spring-loaded plungers 156, 157. The plungers 156 locate the units in correct position after each step and the plungers 157 press the sleeves 27 out of the bores 134 on to the terminals 22 of a switch 23 which is transferred to a shoot 164.